We’ve all been to a restaurant and ordered an entrée only to have the wait person suggest some additional side or appetizer based on our entrée selection. This is known as “upselling.” We’ve also been in the situation where we have seen a newspaper advertisement for a product on sale only to get to the store to see another version of the sale product that is better but not on sale. This is known as a “loss leader.”

It is probable that you’ve bought the extra side dish or the “non-sale” more expensive item in both of the situations above at least once.